Valve timing adjusting apparatus for internal combustion engine

ABSTRACT

A valve timing adjusting apparatus comprises: a housing 31 integrally provided to a timing pulley driven by an engine crank shaft, a shoe hosing 33 which is connected to the housing 31 and having a plurality of shoes 33a protruded from the inner surface of housing, and a rotor 34 which is rotatably accommodated in the she housing 33, wherein a plurality of vanes protrudedly provided on the external surface of the rotor divide the space made by the plurality of shoes 33a into an angle-delay hydraulic cabin and an angle-advance hydraulic cabin, and the rotor 34 is coaxially connectable to the camshaft 2. The valve timing adjusting apparatus further comprises: a protruded portion 46 protruding in the axial direction of the housing 31 on either one of the abutting surfaces of the rotor 34 and the housing 31, and a recess 47 to be fitted to the protruded portion 46 is formed in the other of the rotor 34 and the housing 31.

CROSS-REFERENCE TO THE RELATED APPLICATION

[0001] This Application is a continuation of International ApplicationNo. PCT/JP99/05864, whose international filing date is Oct. 22, 1999,the disclosures of which Application are incorporated by referenceherein, and which International Application was not published inEnglish.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a valve timing adjustingapparatus, which variably controls the timing for opening and/or closingeither an intake valve or an exhaust valve in accordance with thedriving state of an internal combustion engine.

[0004] 2. Description of the Related Art

[0005] There have been proposed various vane-type valve timing adjustingapparatuses for internal combustion engine so far, a case in point beingthe one disclosed in Japanese Patent Application Laid-Open No. 9-60507.

[0006]FIGS. 1 and 2 are illustrations showing a conventional vane-typevalve timing adjusting apparatus for internal combustion engine, whichis mounted onto a camshaft of an internal combustion engine (hereinaftermay be referred to just as an “engine”), wherein FIG. 1 is alongitudinal sectional view of the valve-timing adjusting apparatus, andFIG. 2 is a sectional view observed along the line II-II of FIG. 1. InFIG. 1, reference numeral 1 denotes a chain sprocket, which receives arotational force transmitted from a crank shaft (not shown) functioningas a drive shaft of the engine by way of a chain (not shown), androtates in synchronism with the crank shaft. The camshaft 2 functioningas a slave shaft receives the driven force transmitted from the chainsprocket 1, and opens and/or closes at least one of an intake valve (notshown) and an exhaust valve (not shown). The camshaft 2 is rotatablewith respect to the chain sprocket 1 within a predetermined angle.

[0007] As shown in FIG. 1, the chain sprocket 1 and a shoe housing 3functioning as a housing member, and also a front plate 4 functioning asa covering member are coaxially fixed by a bolt 5. The inner surface ofthe boss la of the chain sprocket 1 is engaged with the end portion 2 aof the camshaft 2 in a relatively rotatable manner. The position of theshoe housing 3 and that of the front plate 4 in the rotational angulardirection are predetermined by a knock pin 6, whereas the position ofthe chain sprocket 1 and that of the shoe housing 3 in the rotationalangular direction are predetermined by another knock pin (not shown).

[0008] As shown in FIGS. 1 and 2, the shoe housing 3 containstrapezoidal shoes 3 a and 3 b facing to each other. The opposing facesof these shoes 3 a and 3 b are formed respectively in a sectionallycircular arc shape, and in two gaps made by these shoes 3 a and 3 b inthe circumferential direction thereof, there are formed fan shape spacesfor respectively accommodating vanes 7 a and 7 b (later explained) of avane rotor 7. The vane rotor 7 is generally composed of the fan shapevanes 7 a and 7 b and also a support member 7 c for supporting thesevanes 7 a and 7 b, which support member being integrally fixed to thecamshaft 2 by a bolt 8. The vanes 7 a and 7 b are rotatably accommodatedin the fan shape spaces formed in the circumferential direction of therespective shoes 3 a and 3 b. The in-low section 7 d of the vane rotor 7is coaxially engaged with the end portion 2 a of the camshaft 2, and theposition of the vane rotor 7 and that of the camshaft 2 in therotational angular direction thereof are predetermined by a knock pin(not shown). The cylindrical protruded portion 9 integrally fixed to thevane rotor 7 is fitted into the inner peripheral surface of the frontplate 4 in a relatively rotatable manner. There are formed smallclearances 10 and 11 between the external peripheral surface of the vanerotor 7 and the inner peripheral surface of the show housing 3, whereinthe vane rotor 7 and the shoe housing 3 are formed in a relativelyrotatable manner. There are formed a retarding hydraulic chamber 12between the shoe 3 a and the vane 7 a, and a retarding hydraulic chamber13 formed between the shoe 3 b and the vane rotor 7 b, whereas there areformed an advancing hydraulic chamber 14 between the shoe 3 a and thevane 7 b, and also an advancing hydraulic chamber 15 between the shoe 3b and the vane 7 a. Further, there are formed oil paths at the oppositeaxial end surfaces of the support member 7 c of the vane rotor 7,wherein at its abutting section against the cylindrical protrudedportion 9, an oil path 16 is provided as a groove-shape path is formed,whereas at its abutting portion against the camshaft 2, an oil path 17is provided as a groove-like path is formed, both shifted from eachother along the respectively circumferential directions in the form of aletter “C”. The oil path 16 is connected to the retarding hydraulicchambers 12 and 13 by way of other oil paths 18 and 19, and is furtherconnected to an oil chamber (not shown) by way of another oil path 20.The oil path 17 is connected to the advancing angle hydraulic chambers14 and 15 by way of other oil paths 22 and 23. An oil path 24 isconnected to an oil path 25 formed within the camshaft 2 at the abuttingportion of the support member 7 c against the camshaft 2 in the axialdirection, wherein the oil path 16 is connected to the oil path 24 atthe abutting portion of the support member 7 c against the cylindricalprotruded portion 9. The oil path 17 is connected to an oil path (notshown) formed within the camshaft 2 at the abutting portion of thesupport member 7 c against the camshaft 2.

[0009] By this construction above, the camshaft 2 and the vane rotor 7are formed such that they are coaxially and relatively rotatable withrespect to all the chain sprocket 1, the shoe housing 3 and also thefront plate 4. Specially, the vane rotor 7 maintains its coaxialposition with the shoe housing 3 by suppressing the shoes 3 a and 3 btowards the radially external direction of the vane rotor 7 by use of achip seal 27 attached to the groove portion 7 d formed in the externalperipheral wall of its support portion 7 c.

[0010] It is to be noted that when attaching the valve timing adjustingapparatus as constructed above to the engine main body, after theabove-mentioned vane rotor 7 is mounted to the shoe housing 3 and thefront plate 4 in a coaxially and relatively rotatable manner, the thusformed component is transported to an engine body assembling factory asan engine component in many cases. At the time of this transport,external forces such as vibration and so on can be exerted to thecomponents such as the above-mentioned vane rotor 7 and so on.

[0011] However, in the case where such an external force as thevibration during the transport is exerted against the urging force ofthe chip seal 27 toward the radial direction of the above-mentioned vanerotor 7, the coaxial position of the vane rotor 7 with respect to theshoe housing 3 and so on is erroneously shifted, thereby to cause such aproblem that the mountability of the vane rotor 7 onto the camshaft 2becomes deteriorated.

[0012] The present invention has been proposed to solve the problemsaforementioned, and it is an object of the present invention to providea valve timing adjusting apparatus for internal combustion engine whichis provided with a means for regulating the positional relation in theradial direction between the rotor and the housing, and also thatbetween the rotor and the covering member.

SUMMARY OF THE INVENTION

[0013] The valve timing adjusting apparatus according to the presentinvention is constructed in such a manner that it comprises: a housingintegrally formed with a rotational member that is driven by acrankshaft at an engine side, a shoe case, which is connected to thehousing and having a plurality of shoes protruded from the inner surfaceof the shoe case, and a rotor which is rotatably accommodated in theshoe case, and is formed with a plurality of vanes protruding from itsexternal peripheral surface, which vanes dividing each of the spacesbetween the plurality of adjacent shoes into a first hydraulic cabin anda second hydraulic cabin, wherein the rotor is coaxially connectablewith a camshaft for driving a valve of an engine system to be openedand/or shut, wherein either one of the abutting surfaces between therotor and the housing is formed with a protruded portion projecting inthe axial direction of the housing, and the other of the abuttingsurfaces is formed with a recess to be fitted with the protrudedportion. Due to this construction, the relative movements of the rotorand the housing in the radial directions can be regulated by the fittingof the protruded portion and the recess, and thus, since the relativemovements of the case and the rotor in the radial direction can also beregulated, even if an external force is applied during the transportthereof, the coaxial position of the rotor with the case can be securelymaintained, and thus the mountability thereof onto the camshaft of theengine main body can be greatly improved.

[0014] Further, according to the present invention, the protrudedportion and the recess can be fitted in a slidable manner in the axialdirection of either the rotor or the housing. Due to this construction,the fitting of the protruded portion with the recess can be greatlyfacilitated.

[0015] Further, according to the present invention, the protrudedportion is a first annular projection coaxially formed with the rotor ona first boss section which is provided at either one of the axialopposite end portions of the rotor, and the recess is formed in acovering member covering one end of the axial opposite end portions andslidably fitted with the first annular projection, which recess being afirst through hole coaxial with the covering member. Due to thisconstruction, the relative movements of the covering member and therotor in the radial direction are regulated by the fitting of the firstthrough hole with the first annular protruded portion, and since thepositional relation of the casing connected to the covering member andthe rotor is regulated in the radial direction, even if an externalforce is applied thereto during the transport thereof, the coaxialposition of the rotor with respect to the casing member can bemaintained, and thus the mountability thereof onto the camshaft of theengine main body side can be greatly improved.

[0016] Still further, according to the present invention, the protrudedportion further contains a second annular projection coaxially formedwith the rotor on a second boss section which is provided at the otherend of the axial opposite end portions, and the recess further containsa second through hole coaxially formed in the housing, and silidabllyfitted with the second annular projection. Due to this construction, inaddition to the regulation of the positional relation between the casingand the rotor, the movement of the rotor and the housing in the radialdirection can also be regulated by fitting of the second annularprotruded portion and the second through hole, so that even if anexternal force is applied thereto during the transport thereof, thecoaxial position of the rotor with respect to the housing can besecurely maintained, and thus the mountability thereof onto the camshaftof the engine main body side can be greatly improved.

[0017] Yet still further, the valve timing adjusting apparatus accordingto the present invention is constructed in such a manner that itcomprises: housing integrally formed with a rotational member that isdriven by a crankshaft at an engine side, a shoe case, which isconnected to the housing and having a plurality of shoes protruded fromthe inner surface of the shoe case, and a rotor which is rotatablyaccommodated in the shoe case, and is formed with a plurality of vanesprotruding from its external peripheral surface, which vanes dividingeach of the spaces between the plurality of adjacent shoes into a firsthydraulic cabin and a second hydraulic cabin, wherein the rotor iscoaxially connectable with a camshaft for driving a valve of an enginesystem to be opened and/or shut, a covering member for covering eitherone of the opposite axial ends of the rotor, and a bias means, which isdisposed at the opposite side of the rotor and the shoe case withrespect to the covering member, and urges the rotor against the shoecase either in the advancing direction or the retarding direction,wherein either one of the abutting surfaces between the rotor and thehousing is formed with a protruded portion projecting in the axialdirection of the housing, and the other of the abutting surfaces isformed with a recess to be fitted with the protruded portion, whereinone part of the protruded portion is a fixed end of the bias means. Dueto this construction, the relative movements of the rotor and thehousing in the radial directions can be regulated by the fitting of theprotruded portion and the recess, whereby even if an external force isapplied thereto during the transport thereof, the coaxial position ofthe rotor with respect to the housing can be securely maintained, andthus the mountability thereof onto the camshaft of the engine main bodyside can be greatly improved.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a longitudinal sectional view showing a conventionalvane-type valve timing adjusting apparatus.

[0019]FIG. 2 is a sectional view observed along the line II-II of FIG.1.

[0020]FIG. 3 is a longitudinal sectional view showing an importantportion of the valve timing adjusting apparatus according to a firstembodiment of the present invention.

[0021]FIG. 4 is a sectional view observed along the line IV-IV of FIG.3.

[0022]FIG. 5 is a partly magnified sectional view showing the portionsV1 and V2 of FIG. 4.

[0023]FIG. 6 is a longitudinal sectional view showing an importantportion of the valve timing adjusting apparatus according to a secondembodiment of the present invention.

[0024]FIG. 7 is a longitudinal sectional view showing an importantportion of the valve timing adjusting apparatus according to a thirdembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Several embodiments for carrying out best the present inventionare now explained with reference to attached drawings, in order toexplain the present invention to details.

First Embodiment

[0026]FIG. 3 is a longitudinal sectional view showing an importantportion of the valve timing adjusting apparatus according to a firstembodiment of the present invention. FIG. 4 is a sectional view observedalong the line IV-IV of FIG. 3, and FIG. 5 is a partly magnifiedsectional view showing the portions V1 and V2 of FIG. 4. Note that as tothe components of a valve timing adjusting apparatus for internalcombustion engine according to the first embodiment, the same or similarmembers as or to those in FIGS. 1 and 2 are put the same referencenumerals for omitting a repetition of the same explanation.

[0027] In these figures, reference numeral 30 denotes a timing pulley asa rotating member that is driven in synchronism with the rotation of theengine by way of an endless belt (not shown), and numeral 31 denotes ahousing of a substantially disk shape integrally formed with the timingpulley 30. The center portion of the housing 31 is formed with a throughhole 32 so as to be fitted with the camshaft 2 inserted therethrough.There is provided a shoe housing 33 as a casing and the vane rotor 34accommodated in this shoe housing 33 between the housing 31 and thefront plate 4. The inner peripheral surface of the shoe housing 33 isformed with four shoes 33 a, 33 b, 33 c and 33 d, whereas the externalperipheral surface of the vane rotor 34 is formed with four vanes 34 a,34 b, 34 c and 34 d. In this configuration, the vane 34 is accommodatedin the fan shape space between the shoes 33 a and 33 b, the vane 34 b isaccommodated in the fan shape space between the shoes 33 b and 33 c, thevane 34 c is accommodated in the fan shape space between the shoes 33 cand 33 d, and the vane 34 d is accommodated in the fan shape spacebetween the shoes 33 d and 33 a, wherein the respective vanes 34 a, 34b, 34 c and 34 d divide each of the fan shape spaces into the retardinghydraulic chamber 35 as a first hydraulic chamber and the advancinghydraulic chamber 36 as a second hydraulic chamber. The mutuallyadjacent retarding hydraulic chambers 35 and the advancing hydraulicchambers 36 are hampered from being interconnected by the chip seal 37provided to each of the end portions of the shoes 33 a, 33 b, 33 c and33 d, and by the chip seal 38 provided to each of the end portions ofthe vanes 34 a, 34 b, 34 c and 34 d. It is to be noted that referencenumeral 39 denotes a back spring that makes each of the chip seals 37 tobe brought into contact with the external surface of the vane rotor 34,and a similar back spring (not shown) is provided also to each of theother chip seals 38.

[0028] In FIG. 4, numeral 40 denotes a plunger slidably disposed alongthe axial direction in the through hole 31 a of the housing 31, numeral41 denotes a spring that is disposed in the through hole 31 a of thehousing 31, urging the plunger 40 into the fitting hole 42 of the vanerotor 34, and numeral 43 denotes a plunger oil path for feeding oil intothe fitting hole 42 of the vane rotor 34 and/or exhausting the used oilfrom the fitting hole 42. In the case where oil pressure is not suppliedto this plunger oil path 43, the plunger 40 is fitted into the fittinghole 42 of the vane rotor 34 by the urging force of the spring 41,whereby the relative rotation of the vane rotor 34 and the housing 31 issuppressed. On the other hand, in the case where oil pressure issupplied to the plunger oil path 43, the thus supplied oil pressurepushes the plunger 40 rearward against the urging force of the spring41, and the plunger 40 is separated from the fitting hole 42 of the vanerotor 34, whereby the suppression of relative rotation of the vane rotor34 and the housing 1 is released.

[0029] Note that reference numeral 44 denotes a first oil path providedwithin the camshaft 2, and is connected to the retarding hydraulicchamber 35 for shifting the vane rotor 34 in the retarding direction,whereas reference numeral 45 denotes a second oil path provided alsowithin the camshaft 2, and is connected to the advancing hydraulicchamber 36 for shifting the vane rotor 34 in the advancing direction.

[0030] In FIG. 5, numeral 46 denotes a protruded portion coaxiallyformed with the vane rotor 34 on the abutting surface at which the vanerotor 34 comes into contact with the housing 31, and projects along theaxial direction of the vane rotor 34, whereas numeral 47 denotes arecess portion that is formed coaxially with the housing 31 at theabutting side of the through hole 32 of the housing 31 at which thehousing 31 comes into contact with the bane rotor 34, and is fitted withthe protruded portion 46. The inner surface 47 a of this recess 47 andthe external surface 46 a of the protruded portion 46 are, when thehousing 31 and the vane rotor 34 are to be fitted, slidably fitted inthe axial direction of the vane rotor 34, and the vane rotor 34 and thehousing 31 are relatively rotatable. Note that the front plate 4, theshoe housing 33 and the housing 31 are integrally fixed by a bolt 5.

[0031] Further, the center portion of the protruded portion 46 of thevane rotor 34 is formed with a fixing recess 48 for receiving and fixingthe end portion 2 a of the camshaft 2, and an opening of this fixingrecess 48 is formed with a slant portion 48 a for guiding the endportion 2 a of the camshaft 2 when inserting the camshaft 2 thereto.

[0032] Next, the method of mounting the above-explained valve-timingadjusting apparatus to the engine body is explained as below.

[0033] First, the vane rotor 34 is accommodated in the shoe housing 33,and the front plate 4 is attached to the end portion of these vane rotor34 and shoe housing 33. Thereafter, when attaching the vane rotor 34 tothe housing 31, the protruded portion 46 of the vane rotor 34 is fittedinto the recess 47 of the housing 31 thereby to compose an engine part,and the thus composed engine part is transported to the assemblingfactory of the engine body. Note that the protruded portion 46 and therecess 47 are fitted in a slidable manner along the axial direction ofthe vane rotor 34, and further the vane rotor 34 and the housing 31 aremade relatively rotatable, although the vane rotor 34 is delimited itsmovement in the radial direction by this fitting operation of theprotruded portion 46 and the recess 47. Thus, even if an eternal forceis exerted in the radial direction of the vane rotor 34 against theurging force of the chip seals 37 and 38 during the transport thereof,the displacement of the coaxial point of the vane rotor 34 with respectto the housing 31 can securely be prevented, so that the mountability ofthe vane rotor 34 onto the camshaft 2 can be greatly improved.Thereafter, at the engine body assembling factory, one end portion 2 aof the camshaft 2 is inserted into the through hole 32 of the housing31. Here, the end portion 2 a of the camshaft 2 is inserted into therecess 48 of the vane rotor 34 coaxially mounted to the housing 31,wherein the end portion 2 a of the camshaft 2 is securely guided intothe fixing recess 48 owing to the slant portion 48 a, and is fixed tothe vane rotor 34 by a bolt 49 in a coaxial manner.

[0034] Next, the operation of the valve timing adjusting apparatus forinternal combustion engine is now explained below.

[0035] First, in the case where the camshaft 2 is to be retarded interms of timing with respect to the rotation angle of the timing pulley30, oil is provided from an oil providing source (not shown) into theretarding hydraulic chambers 35 out of the two types of hydraulicchambers; namely the advancing hydraulic chambers 36 and the retardinghydraulic chambers 35, which are dividedly formed by the vanes 34 a, 34b, 34 c and 34 d, and at the same time oil is exhausted from theadvancing hydraulic chambers 36, whereby the camshaft is rotated, takingadvantage of the difference of oil pressures at the respective sides ofeach of the vanes 34 a, 34 b, 34 c and 34 d. On this occasion, when thetiming pulley 30 is rotated, the plunger 40 urged toward the camshaft 2by the spring 41 is inserted into the fitting hole 42 of the vane rotor34, and thus the relative rotation between the camshaft 2 which isfirmly connected to the vane rotor 34 and the timing pulley 30 issuppressed.

[0036] As explained above, since it is intended according to this firstembodiment that the coaxial position of the vane rotor 34 with respectto the housing 31 can be secured by fitting the protruded portion 46provided to the vane rotor 34 in the axial direction into the recess 47provided in the housing 31, the mountability of the vane rotor 34 ontothe camshaft 2 can be greatly improved.

[0037] It should be noted that although in this embodiment the recess isformed at the housing 31 side and the protruded portion is provided atthe vane rotor 34 side, the protruded portion can be provided at thehousing 31 side, and the recess can be formed at the vane rotor 34 side,but on condition that the relative rotations of the housing 31 and thevane rotor 34 are not thereby delimited. Even in this case, thedisplacement of the coaxial point of the vane rotor 34 with respect tothe housing 31 can securely be prevented, so that the mountability ofthe vane rotor 34 onto the camshaft 2 can be greatly improved.

Second Embodiment

[0038]FIG. 6 is a longitudinal sectional view showing an importantportion of the valve timing adjusting apparatus according to a secondembodiment of the present invention. Note that the same or similarmembers as or to those in FIGS. 3, at and 5 are put the same referencenumerals for omitting a repetition of the same explanation.

[0039] The technical feature of this second embodiment resides in thatthe vane rotor 34 is fitted not only with the housing 31 in thevalve-timing adjusting apparatus to be attached to the air intake sideof an engine, just as the first embodiment, but also fitted with thefront plate at That is, the protruded portion 46 of the vane rotor 34 islargely protruded much more than the case of the first embodiment so asto be a boss section (first boss), and threads through the recess 47 ofthe housing 31. The external peripheral surface 46 a of the vane rotor34 and the inner peripheral surface 47 a of the recess 47 are fitted inan axially slidable manner, and the vane rotor 34 and the housing 31 areset in the relatively rotatable manner.

[0040] The center portion of the vane rotor 34 is formed with acylindrical protruded portion 50 projecting in the axial direction as aboss section (second boss) at the opposite side of the protruded portion46, and the center portion of the front plate at is formed with athrough hole 51. The external peripheral surface 50 a of the protrudedportion 50 and the inner peripheral surface 51 a of the through hole 51are slidably fitted in the axial direction of the vane rotor 34, and thevane rotor 34 and the front plate at are formed in the relativelyrotatable manner. Note that the front plate at, the shoe housing 33 andthe housing 31 are integrally fixed by a bolt 5.

[0041] Due to the construction as explained above, in this secondembodiment, not only the protruded portion 46 of the vane rotor 34 isfitted to the recess 47 of the housing 31, but the protruded portion 50of the vane rotor 34 is also fitted into the through hole 51 of thefront plate at, whereby the coaxial point of the vane rotor 34 withrespect to the housing 31 and the front plate at can securely bemaintained.

Third Embodiment

[0042]FIG. 7 is a longitudinal sectional view showing an importantportion of the valve timing adjusting apparatus according to a thirdembodiment of the present invention. Note that the same or similarmembers as or to those of the valve timing adjusting apparatus accordingto the first and second embodiments as shown in FIGS. 3 to 6 are put thesame reference numerals for omitting a repetition of the sameexplanation.

[0043] The technical feature of this third embodiment resides in that inthe valve-timing adjusting apparatus to be attached to the airexhausting side of an engine, two boss sections of the vane rotor 34 arefitted both with the housing 31 and a later-explained unit cover. Thatis, the protruded portion 46 provided at one axial end surface of thevane rotor 34 is fitted into the recess 47 of the housing 31. Further,the other protruded portion 50 of the vane rotor 34 is fitted into thefirst and a second through holes 52 a and 53 a, which are formed in thecenter portion of a first plate 52 attached to both the shoe housing 33and the other axial end surface of the vane rotor 34, and in the centerportion of the second plate 53 attached to the surface of the firstplate 52, respectively in the coaxial manner. These first and secondplates 52 and 53 are fixed to the housing 31 and the vane rotor 34 by afixing bolt 54. The outer periphery of the first plate 52 is bent to thedirection opposite to the vane rotor 34 to make a bent portion 52 b, andthis bent portion 52 holds the second plate 53 and the covering member55, sandwiching the second plate 53 between the bent portion 52 and thecovering member 55. The covering member 55 contains a third through hole55 a for threading therein a bolt 56 used for coaxially fixing the vanerotor 34 and the camshaft 2, and also an accommodating section 55 b thatencloses the third through hole 55 a therein, and also accommodates aspring as a bias means for urging the vanes 34 a, 34 b, 34 c and 34 dtoward the retarding direction or advancing direction with respect tothe shoe housing 33. The spring 57 is wound around the externalperipheral portion of the protruded portion 50 of the vane rotor 34fitted both with the first through hole 52 a of the first plate 52 andthe second through hole 53 a of the second plate 53. The fixed end 57 aof the spring 57 is abutted against the notched portion 50 b of theprotruded portion 50, whereas the top end portion 50 c of the protrudedportion 50 is abutted against the inner peripheral brim of the thirdhole 55 a of the covering member 55. Note that the first plate 52, thesecond plate 53 and the covering member 55 configure together a unitcover 58. Further, In FIG. 7, reference numeral 59 denotes a holder forpositioning the spring 41 that urges the plunger 40 for suppressing therelational movements of the shoe housing 33 and the vane rotor 34.

[0044] Since in this third embodiment of the present invention theprotruded portion 46 of the vane rotor 34 is fitted into the recess ofthe housing 31, whereas the other protruded portion 50 of the vane rotor34 is fitted into the first through hole 52 a of the first plate 52 andthe second through hole 53 a of the second plate 53, there is such aneffect that the coaxial position of the vane rotor 34 with respect tothe housing 31 and to the unit cover 58 can be securely maintained.

[0045] Further, in this third embodiment, since it is arranged such thatthe fixed end 57 a of the spring 57 is abutted against the notchedportion 50 b of the protruded portion 50 of the vane rotor 34, and theurging force of the spring 57 is applied directly to the vane rotor 34,there is such an effect that the components at the above two fittingportions are prevented from slipping off in the axial direction.

[0046] As explained heretofore, the valve timing adjusting apparatusaccording to the present invention is capable of maintaining the coaxialposition of the rotor with respect to both the casing and the housing bydelimiting the positional relation between the rotor and the housing,and that between the rotor and the covering member in the radialdirection, whereby the mountability thereof onto the camshaft can begreatly improved.

What is claimed is:
 1. A valve timing adjusting apparatus comprising: ahousing integrally formed with a rotational member that is driven by acrankshaft at an engine side, a shoe case, which is connected to saidhousing and having a plurality of shoes protruded from the inner surfaceof said shoe case, and a rotor which is rotatably accommodated in saidshoe case, and is formed with a plurality of vanes protruding from itsexternal peripheral surface, said vanes dividing each of the spacesbetween the plurality of adjacent shoes into a first hydraulic cabin anda second hydraulic cabin, wherein said rotor is coaxially connectablewith a camshaft for driving a valve of an engine system to be openedand/or shut, wherein either one of the abutting surfaces between saidrotor and said housing is formed with a protruded portion projecting inthe axial direction of the housing, and the other of said abuttingsurfaces is formed with a recess to be fitted with said protrudedportion.
 2. The valve timing adjusting apparatus according to claim 1characterized in that said protruded portion and said recess can befitted in a slidable manner in the axial direction of either said rotoror said housing.
 3. The valve timing adjusting apparatus according toclaim 1, wherein said protruded portion is a first annular projectioncoaxially formed with said rotor on a first boss section which isprovided at either one of the axial opposite end portions of said rotor,and said recess is formed in a covering member covering one end of theaxial opposite end portions and slidably fitted with said first annularprojection, said recess being a first through hole coaxial with saidcovering member.
 4. The valve timing adjusting apparatus according toclaim 3, wherein said protruded portion further contains a secondannular projection coaxially formed with said rotor on a second bosssection which is provided at the other end of said axial opposite endportions, and said recess further contains a second through holecoaxially formed in said housing, and silidablly fitted with said secondannular projection.
 5. A valve timing adjusting apparatus comprising:housing integrally formed with a rotational member that is driven by acrankshaft at an engine side, a shoe case, which is connected to saidhousing and having a plurality of shoes protruded from the inner surfaceof said shoe case, and a rotor which is rotatably accommodated in saidshoe case, and is formed with a plurality of vanes protruding from itsexternal peripheral surface, said vanes dividing each of the spacesbetween the plurality of adjacent shoes into a first hydraulic cabin anda second hydraulic cabin, wherein said rotor is coaxially connectablewith a camshaft for driving a valve of an engine system to be openedand/or shut, a covering member for covering either one of the oppositeaxial ends of said rotor, and a bias means, which is disposed at theopposite side of said rotor and said shoe case with respect to saidcovering member, and urges said rotor against said shoe case either inthe advancing direction or the retarding direction, wherein either oneof the abutting surfaces between said rotor and said housing is formedwith a protruded portion projecting in the axial direction of thehousing, and the other of said abutting surfaces is formed with a recessto be fitted with said protruded portion, wherein one part of saidprotruded portion is a fixed end of said bias means.